1. Field of the Invention
The present invention relates to a substrate processing apparatus that coats a semiconductor wafer with a resist solution, processes it to develop a resist film after exposure to light and inspects the status of the processed wafer, and to a substrate processing method.
2. Description of the Related Art
Photolithography technology is used, for example, in the manufacturing of semiconductor devices to form determined resist patterns on a substrate such as a semiconductor wafer by coating it with a resist solution and by exposing the resist film to light using photo mask and further subjecting it to developing processing. Conventionally, a resist coating/developing system has been used in such series of processes.
The resist coating/developing system is equipped with various kinds of processing unit for the series of processes necessary in coating resist and developing processing. For example, equipped are the resist coating unit for coating the wafer with the resist solution, the developing unit for developing the light-exposed wafer and a heating unit for heating the wafer after the resist coating and developing processing.
Also, linked to the resist coating/developing system is a inspecting/measuring unit for inspecting and/or measuring the status of the processed wafer after developing processing. The inspecting/measuring unit inspects and/or measures the resist pattern line width and the layering of the resist patterns and base patterns, unevenness of the resist coating and developing defects.
However, in a system that link conventional inspecting/measuring unit to the resist coating/developing system, when the inspecting/measuring unit should experience a system failure and the inspecting/measuring of wafer is no longer possible, processing in the resist coating/developing system will be cancelled thereby causing many defective wafers to be produced.
Also, if the inspecting/measuring unit is linked to the resist coating/developing system, they distort the shape of the entire system because they protrude from the resist coating/developing system. Therefore, when installing the entire system into a clean room, it is necessary for the installation area to be wider than the inspecting/measuring unit.
Furthermore, because generally the throughput of the resist coating/developing system and the inspecting/measuring unit are different and wafers are handed over between the resist coating/developing system and the inspecting/measuring units using a wafer transfer device established on the resist coating/developing system, a wafer transfer rate in the resist coating/developing system decrease which causes the problem of decreased throughput of the entire system.
An object of the present invention is to provide a substrate processing apparatus and substrate processing method that can prevent the generation of defective substrates in the event circumstances disallow substrates for inspecting/measuring to be transferred into a device that inspects/measures substrates. Still another object of the present invention is to provide a substrate processing apparatus that can efficiently transfer substrates and that has a compact footprint.
According to a first aspect of the present invention, there is provided a substrate processing apparatus that performs predetermined process on a series of substrates one by one comprising
a cassette station that holds cassettes storing a plurality of substrates;
a process station for performing predetermined process on a substrate transported out from said cassettes;
an inspection station for performing predetermined inspection and/or measurement on a substrate that have completed said process at said process station;
a substrate transfer means for transferring a substrate between said cassette station, said process station and said inspection station; and
a transfer control mechanism for controlling the operations of said substrate transfer means;
wherein said inspection station comprises:
an inspecting/measuring unit for performing the inspection and/or measurement on a substrate transferred from said process station to said inspection station; and
an emergency stage unit into which a inspection/measurement substrate for the inspection and/or measurement using said inspecting/measuring unit is temporarily transferred, said emergency stage unit being established in parallel to said inspecting/measuring unit;
and wherein said transfer control mechanism controls said substrate transfer means to transfer said inspection/measurement substrate from said process station to said cassette station via said substrate stage when circumstances disallow transferring substrates into said inspecting/measuring unit.
In such a substrate processing apparatus, when circumstances disallow the transferring of the substrate into the inspecting/measuring unit for inspecting/measuring, the inspection/measurement substrate is temporarily transferred to the emergency stage unit, then transferred from there to the aforementioned cassette station to continue substrate processing in the substrate processing apparatus. This prevents the generation of defective substrates.
According to a second aspect of the present invention, there is provided a substrate processing apparatus that performs predetermined process on a series of substrates on by one comprising:
a cassette station having a cassette stage for holding a cassette that stores a plurality of substrates and a substrate transfer I/O device for transferring a substrate into and out of said cassette placed on said cassette stage;
a process station for performing predetermined process on a substrate transferred out from said cassette;
an inspection station having an inspecting/measuring unit for performing predetermined inspection and/or measurement on a substrate that have completed process at said process station, said inspection station being established between said cassette station and said process station; and
a selecting means for selecting inspection/measurement substrates for the inspection and/or measurement using said inspecting/measuring unit from substrates transferred into said inspection station;
wherein said process station comprises:
a process portion in which the predetermined process is performed on a substrate;
a substrate transfer device for transferring a substrate into and out of said process portion and transfers each substrate having been processed at said process portion to said inspection station in the same order as transferred from said cassette;
and wherein said inspection station further comprises:
a temporary stage unit that temporarily holds non-inspection substrates other than said inspection/measurement substrates; and
a substrate transfer means for transferring a substrate according to the order transferred from said cassette, from said cassette station to said process station and transferring a substrate from said inspection station to said cassette station according to the order transferred into said inspection station, and transferring a substrate into and out of said inspecting/measuring unit and said temporary stage unit.
By establishing the inspection station in this way between the cassette station and the process station, the footprint of the apparatus can be made more compact and can enable the efficient transferring of substrates. If an emergency stage unit for transferring a inspection/measurement substrate is established into the inspection station for when circumstances arise that disallow the transferring of the substrate into the inspecting/measuring unit, and with a structure that enables the substrate transfer means to access this emergency stage unit, the inspection/measurement substrate can be transferred into the cassette station via this emergency stage unit when circumstances arise disallow the transferring of the substrate into the inspecting/measuring unit. This enables the processing of substrates in the substrate processing apparatus to continue and prevents the generation of useless substrates.
According to a third aspect of the present invention, there is provided a substrate processing method, comprising steps of:
transferring a substrate from a cassette that stores a plurality of substrates to a process station for performing predetermined process on a substrate;
processing substrates one by one in said process station that are transferred into said process station;
transferring each substrate that have completed the process in said process station from said process station to an inspection station for performing inspecting/measuring a state of processed substrate, said inspection station having an inspecting/measuring unit for performing predetermined inspection and/or measurement on a substrate;
selecting inspection/measurement substrates for the inspection and/or measurement using said inspecting/measuring unit from substrates transferred to said inspection station;
temporarily transferring said inspection/measurement substrates to a emergency stage unit that established in parallel with said inspecting and/or measuring unit when circumstances arise that disallow transferring of said inspection/measurement substrates into said inspecting/measuring unit; and
transferring each substrate transferred into said emergency stage unit to said cassette station.
According to a fourth aspect of the present invention, there is provided a substrate processing method comprising steps of:
transferring substrates one by one to from a cassette that stores a plurality of substrates to a process station for performing predetermined process on substrates according to the order that substrates are arranged in said cassette;
processing substrates one by one in said process station that are transferred into said process station;
transferring each substrate that have completed process in said process station from said process station to an inspection station for performing inspecting/measuring a state of processed substrate in the same order as the substrates were transferred from said cassette, said inspection station having a inspecting/measuring unit for performing predetermined inspection and/or measurement on a substrate;
selecting inspection/measurement substrates for the inspection and/or measurement using said inspecting/measuring unit from substrates transferred to said inspection station;
temporarily transferring said inspection/measurement substrates to an emergency stage unit that holds a substrate and established in parallel with said inspecting/measuring unit when circumstances arise that disallow transferring of said inspection/measurement substrates into said inspecting/measuring unit, in case where each of said inspection/measurement substrates is transferred to said inspecting/measuring unit,
transferring non-inspection substrates other than said inspection/measurement substrates to a temporary stage unit that holds a substrate and established in parallel with said inspecting/measuring unit, in the order of transfer to said inspection station; and
transferring each substrate from said inspecting/measuring unit, said emergency stage unit and said temporary stage unit to said cassette station in the order of transfer to said inspection station.
In such substrate processing methods, when circumstances disallow the transferring of substrates into the inspecting/measuring unit for inspection/measurement, the inspecting/measuring of the inspection/measurement substrates cannot be performed, but the processing of substrates in the substrate processing apparatus can continue, by transferring the inspection/measurement substrate to the emergency stage unit. This prevents the generation of process-defective substrates.
According to a fifth aspect of the present invention, there is provided a substrate processing method comprising steps of:
transferring substrates one by one from a cassette that stores a plurality of substrates to a process station for performing predetermined process on substrates according to the order that substrates are arranged in said cassette;
processing substrates one by one in said process station that are transferred into said process station;
transferring each substrate that have completed process in said process station from said process station to an inspection station for performing inspecting/measuring a state of processed substrate in the same order as the substrates were transferred from said cassette, said inspection station having a inspecting/measuring unit for performing predetermined inspection and/or measurement on a substrate;
selecting inspection/measurement substrates for the inspection and/or measurement using said inspecting/measuring unit from substrates transferred to said inspection station;
temporarily transferring said inspection/measurement substrates to said inspecting/measuring unit when circumstances arise that disallow the inspection and/or measurement of said inspection/measurement substrates using said inspecting/measuring unit, but transferring of said inspection/measurement substrates into said inspecting/measuring unit is permitted, in case where each of said inspection/measurement substrates is transferred to said inspecting/measuring unit;
transferring said non-inspection substrates to a temporary stage unit that holds a substrate and established in parallel with said inspecting and/or measuring unit, in the order of transfer to said inspection station;
transferring non-inspection substrates other than said inspection/measurement substrates to a temporary stage unit that holds a substrate and established in parallel with said inspecting/measuring unit, in the order of transfer to said inspection station; and
transferring each substrate from said inspecting/measuring unit and said temporary stage unit to said cassette station in the order of transfer to said inspection station.
With this substrate processing method, when circumstances arise that disallow the inspecting/measuring of substrate using the inspecting/measuring unit, such as a failure, but it is possible to place substrates in the inspecting/measuring unit, the inspecting/measuring of the inspection/measurement substrates is not performed, but the processing of substrates in the substrate processing apparatus can continue, by using the inspecting/measuring unit as a unit to temporarily hold substrates. This prevents the generation of process-defective substrates.